package com.gxx.record.gtja;

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

/** 
 * 打印对象
 * 逻辑：多线程按顺序打印1,2,3...,n,n+1,n+2,...,2n,2n+1,2n+2...
 * @author Gxx
 */
public class PrintObject {
	/**
	 * 锁
	 */
	private Lock lock = new ReentrantLock();
	
	/**
	 * 条件
	 */
	private List<Condition> conditionList = new ArrayList<Condition>();
	
	/**
	 * 打印索引，从1,2,3...n,1,2,3...
	 */
	private int index = 1;
	/**
	 * 线程数
	 */
	private int n;
	/**
	 * 轮次
	 */
	private int k = 0;
	
	/**
	 * 构造方法
	 * @param num
	 */
	public PrintObject(int num) {
		for(int i=0;i<num;i++) {
			conditionList.add(lock.newCondition());//新增条件
		}
		this.n = num;
	}
	
	/**
	 * 打印
	 * @param i 线程索引
	 */
	public void print(int i) {
		lock.lock();//锁
		try {
			if(index != i) {
				conditionList.get(i - 1).await();//挂起
			}
			System.out.print(k*n+i + ",");//打印
			index ++;
			if(index > n) {
				index = 1;
			}
			Thread.sleep(100);
			conditionList.get(index - 1).signal();//唤醒
		} catch(Exception e) {
			e.printStackTrace();
		} finally {
			lock.unlock();//释放锁
		}
	}
}